The bearing structure for conventional cooling fan main comprises a bearing, oil seal, washer, C-clamp and other parts, it usually takes great time, labor and cost to assemble. Under long time use, the bearing will produce mechanical noise, or runs not smoothly and the service life is therefore shortened substantially. Now there emerges a named “Efficient bearing” as shown in FIG. 5 which proclaims less parts required in assembly.
The “efficient bearing” as shown in FIG. 5, the leading edge of body 11′ grows into the localized flange 12′ with a round project 13′. The bearing 1′ is placed in the hub of the cooling fan. The base 2′ of cooling fan has an upward sleeve 21′ and the rotor winding 22′ encircles the sleeve 21′. The rotor shaft 25′ mounted on the hub 24′ of the blade 23′ can be threaded downward into the sleeve 21′ and inserted downward into the bearing 1′. By the semicircular parts of the lower end of the rotor shaft 25′ conduced to round tip 26′ which forces the localized flange 12′ stretching outward. After the round tip 26′ of the rotor shaft 25′ passes the localized flange 12′, the round project 13′ of the localized flange 12′ insert the groove 27′ of the rotor shaft 25. The round tip 26′ will rest in the recess 31′ of the seat 3′ so the seat 3′ seals the base 2′ of the blade 23′.
This forms a complete assembly of the blade assembly.
In this prior art of the bearing structure, it requires the seat 3′ to seal the opening of the base 2′. Although, the recess 31 of the seat 3, with the semicircular parts of the lower end of the rotor shaft 25′ conduced to round tip 26′, and provide support for the down edge of blade 23′, but, this bearing design including the body 1′ and seat 3′ leaves room for improvement.
The repulsive force jointly produced by the permanent magnet 4′ contained in the hub 24′ of the blade 23′ and the rotor winding 22′ pushes the blade 23′ to rotate and the blade 23′ will float up and down in the appropriate room and maintain the proper displacement to gain self-adjusted balance. The round project 13′ of the localized flange 12′ retains closely on the groove 27′ of the rotor shaft 25′, while the blade 23′ is rotating, the round project 13′ of the localized flange 12′ will confines the up and down displacement of the blade 23′. The tight contact of the round project 13′ and the groove 27′ generates great abrasive resistance, which not only destabilizes the smooth operation of the blade but also shortens the service life.